Traffic congestion in a network causes many problems including disruption of services, delayed transmission, and system outage. The congestion may occur when a particular node in the network becomes saturated or overloaded with connections and service calls.
A network node may be come congested for a number of reasons. First, a flood of packets may transit through the node during some peak hours due to high demand, causing congestion. Second, the node may have resource problems such as memory capacity, bandwidth unavailability. Third, the node may undergo some maintenance mode switchover where resumption of calls would take longer that the stipulated outage time.
One technique to address the congestion problem is to drop or reject new call requests. This technique imposes a burden on the already congested node to execute a task to process the calls before rejecting them. Consequently, there are numerous crankbacks in the network, resulting in degraded performance and loss of revenue for the carrier. For service-oriented applications such as high availability applications, this congestion is undesirable.